1. Field of the Invention
The present invention generally relates to shipping containers, and more specifically to reusable shipping containers that are designed to be moved via forks attached to a lift vehicle or by a pallet jack or similar apparatus.
2. General Background of the Invention
Various types of reusable containers have long been used in the field of material handling. These containers generally include a base that forms the bottom of the container, a forkstrap assembly that may or may not be integral to the base, and sidewalls extending upward from the base. The forkstrap assembly typically defines two pairs of parallel fork slots with the fork slots of each pair being perpendicular to the fork slots of the other pair. These fork slots traverse the bottom of the base and are designed to accept the forks of a forklift or similar device for moving the container. Typically, the bottom of each fork slot is perpendicularly traversed by a plurality of fork straps that prevent a container from tipping off of the forks of a lift when the container is lifted into the air.
These containers are typically moved around warehouses and put on trucks by forklifts. These forklifts drive at considerable speed and can be difficult to handle. As a result these shipping containers tend to incur significant damage to the fork strap and the feet. This damage occurs when the operator of a forklift poorly aligns the forks with the fork slots causing the fork to impact one or more of the feet with significant force. The tip of a fork can directly impact the exterior portion of the perimeter feet on the side facing the lift when the lift approaches the container. The fork can also directly impact an interior side of the feet of the container that are located on the opposite side of container, an interior side of the feet located on one of the sides of the container, or a side of the centrally located feet if the operator causes the forks to enter the fork slots at an angle. The feet of such containers also can experience damage when the operator of a lift uses the edges of the forks to slide a container sideways on the floor without lifting the container. And the sides of the feet are also subject to being sliced by the tips of the forks when the operator of a lift executes a quick turn when the forks are not clear of the container.
Often the damage inflicted by a fork truck can be catastrophic and can render the container unusable, sometimes breaking off large pieces of the base. When this occurs, one must either replace the entire base of the container at a significant cost or purchase a completely new container.
Another type of damage that is very common to these types of containers is that one or more fork straps will break due to abuse. The fork straps are on the container to act as a safety feature when containers are picked up by a fork lift. The fork straps keep the container from tipping off the end of the forks during transport. It is extremely important that the fork straps remain in proper working order. Many known designs include the fork straps that are an integral part of the base. Thus, when the fork strap breaks it is necessary to replace the entire base because it is not possible to replace or repair the strap, thereby causing the owner of the container considerable expense. Other known designs utilize separate fork straps or a separate fork strap assembly that is attached to the bottom of the feet or snap into the feet. The problem with this design is that if a foot is damaged, the fork straps, or fork strap assembly, can no longer be replaced.
Once one or more feet of a container sustain sufficient damage or one or more fork straps are broken, the container can be rendered unusable. Some container designs have addressed this by making the sidewalls of the container removable from the base that defines the bottom of the container and the fork straps such that the sides can be reused with a new base. In practice, however, the entire container is frequently scrapped because the cost of the labor involved in disassembling the damaged container and assembling the old sides to a new base outweighs the cost of a new container.
Some known designs provide some protection to the exterior sides of the feet on the perimeter of the container, but these designs do not address the full scope of the problem because no protection is provided for the other sides of the perimeter feet or the centrally located feet. In addition, the feet and the protection extend down from the base, meaning that there is no means of replacing a damaged foot. These designs also provide only a single layer of protection to the exterior side of the feet that is easily punctured by a direct hit from a fork.
Thus, what is needed is a container design where at least the external impact surface of the feet extends up from the fork straps and that provides multiple layers of impact protection to all sides of the feet, including the central, internal feet, and that further protects the mechanism for connecting the fork straps or forkstrap assembly to the base.
In many applications, the users of containers require a container that has fork straps running in only one direction in order to accommodate to the use of pallet jacks or similar devices that have wheels located at the tips of the fork that have to roll under the container. Such devices typically only lift the container a few inches off of the ground to allow it to be transported across the floor of a warehouse or some similar surface. In such cases, the fork straps make it difficult, if not impossible, to position the pallet jack under the base to lift the container. Known devices simply omit the fork straps in one direction or users cut off the fork straps in one direction. This results in the lessening of the capacity of the container due to the elimination of a plurality of fork straps that stiffen the container. In some cases, the base of the container will be reinforced with metal plates or other material to maintain the capacity of the container, but this increases the weight of the container and may reduce the number of containers that can be shipped in a single truck due to weight restrictions and will result in increased consumption of fuel. Such reinforcement is also costly because it adds additional material and labor to the cost of the container.
Thus, what is needed is a container design that can relocate the fork straps in one direction to accommodate the use of wheeled pallet jacks without lessening the capacity of the container without increasing the weight or cost of the container.
Another issue with known containers is the lack of a standard manner of handling dunnage. Frequently material shipped in such containers requires a great deal of dunnage to prevent the material from being damage. Examples include dividers to prevent painted metal parts from banging against each other damaging the paint or small plastic parts like twist off lids for soft drink bottles that require shelves throughout the container to prevent the weight of the lids from deforming those on the bottom. Known methods of addressing the dunnage problem include the use of disposable dunnage or expensive retrofitting of containers to accept reusable dunnage.
Thus, what is needed is a container design that provides for a standard method of attaching dunnage to the container that will allow the development of standard forms of reusable dunnage that is easily connectable to the container.